title: Prevalence of zygomatic air cell defect: Panoramic radiographic study of a selected Esfehanian population.
abstract: BACKGROUND
  The mastoid pneumatization begins on the 33(rd) week of embryonic life, and continuous up to 8-9 years of age. This air cells is important for surgical perspective. Inadvertent penetration through this anatomical feature during surgical procedures can be disastrous. Aim of this study is to determine the prevalence of zygomatic air cell defect (ZACD) in the Esfehanian population.
  
  
  METHODS
  This was a cross-sectional study. 2600 panoramic radiographs of patients aged between 3 and 90 years were evaluated retrospectively to establish dominant laterality, type and grade amongst these patients. The SPSS 11.5 program was used for the statistical analysis. Mean and standard deviation were used for statistical methods in this study.
  
  
  RESULTS
  ZACD was found in 94 cases, representing a prevalence of 3.6%. 59 cases occurred in females (62.8%) and 35 cases occurred in males (37.2%). Most cases were in their twenties. Unilateral ZACD was found in 70 patients (74.5%) with the half occurring on the right side. In 24 cases (25.5%) was bilateral. 70 of the cases (59.3%) were multilocular type, while 45 (38.1) and 3 (2.6%) were unilocular and trabecular type, respectively. 59 cases were grade 2 (62.8%) and 35 were grade 3 (37.2%).
  
  
  CONCLUSIONS
  The frequency of ZACD amongst Iranian population was more than previous studies. In addition younger population was involved in this group. So it is important for clinicians who are planning to perform temporomandibular joint surgery to assess radiographic imaging thoroughly before the surgery to avoid intraoperative complications.
authors.affiliation: Torabinejad Dental Research Center and Department of Oral and Maxillofacial Radiology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Asieh
authors.initials: A
authors.lastname: Zamaninaser
authors.forename: Roghayeh
authors.initials: R
authors.lastname: Rashidipoor
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Mosavat
authors.forename: Ahura
authors.initials: A
authors.lastname: Ahmadi
keywords: Panoramic radiography; temporomandibular joint; zygomatic air cell defect